4T80 (just kicking around a few ideas) (Page 1/2)
G-Man JAN 21, 10:30 PM
Outside of the Northstar swap, has anyone ever used this transmission in a Fiero? I know it has been attempted in other FWD platforms behind the 3800 and LS4 but nothing I found ever indicated success.

I'm kicking around a V8 swap that will either be an LS4 or Gen2 LT1 and I would prefer an auto over a manual. I know the LS4 will largely bolt to it (except for the rear-most bolt) but then you have the starter issue. The LT would require an adapter and add overall width to the drive train but might make starter mounting a bit easier. At that point, I suppose any flavor of LS would work and it would come down to what I could find locally that I could afford.

I remember the 'Zumwalt' guy had the 80 bolted to an LT1 on his showpiece trailer many years ago. It was probably just that: A showpiece but does anyone know if it ever made it into a working vehicle (shoddy engineering and all)? I'm mainly interested in whether or not it's possible to get that trans to fit our engine bay because it does stick out farther to the drivers side than the 4T65 does.

Thanks,
Gary
Gall757 JAN 22, 09:39 AM
I pulled this info out of an old thread......100 extra pounds in the back of a Fiero would be significant.

Transmissions- Automatic transmissions include torque converter.
Muncie 4 speed- 84.5 lb.
Isuzu 5 speed- 98 lb.
Getrag 5 speed- 101.5 lb.
Manual flywheel, pressure plate, and clutch disc (stock)- 35 lb.
TH125c 3 speed- 151 lb.
TH440T4 / 4T60 4 speed- 177 lb.
4T60E 4 speed- 186 lb.
4T65E 4 speed- 196 lb.
4T80E 4 speed- 296 lb.
gtoformula JAN 22, 12:30 PM
Sounds like a complicated project. As you know, the Northstar starter is under the intake manifold where the camshaft is usually located on a push rod V8 ... no external starter pad to bolt to. Also, if you use an adapter plate then you will need to use machine tolerance shims to move the torque converter back towards the transmission. If not, then the oil pump drive may not work properly with torque converter pushed away. Also, the 4T80E is a computer shift control transmission and will need a controller to function.
fieroguru JAN 22, 02:10 PM

quote
Originally posted by G-Man:

Outside of the Northstar swap, has anyone ever used this transmission in a Fiero? I know it has been attempted in other FWD platforms behind the 3800 and LS4 but nothing I found ever indicated success.

I'm kicking around a V8 swap that will either be an LS4 or Gen2 LT1 and I would prefer an auto over a manual. I know the LS4 will largely bolt to it (except for the rear-most bolt) but then you have the starter issue. The LT would require an adapter and add overall width to the drive train but might make starter mounting a bit easier. At that point, I suppose any flavor of LS would work and it would come down to what I could find locally that I could afford.

I remember the 'Zumwalt' guy had the 80 bolted to an LT1 on his showpiece trailer many years ago. It was probably just that: A showpiece but does anyone know if it ever made it into a working vehicle (shoddy engineering and all)? I'm mainly interested in whether or not it's possible to get that trans to fit our engine bay because it does stick out farther to the drivers side than the 4T65 does.

Thanks,
Gary



I have seen pictures of the 4T80 alongside a SBC in a Fiero, WCF built a turbo 3.4 TDC car (color was blue) with the 4T80, and Bfurches on LS1 tech used one with a turbo LS4 until he fragged it.

Bfurches was using a 24x LS1 ecm to control both the LS4 (24x) as well as the 4T80. It wasn't perfect as that ecm wouldn't control everything within the 4T80.
https://ls1tech.com/forums/...-ls4-4t80e-s475.html
https://ls1tech.com/forums/...e-update-broken.html

[shameless plug] I sell a bolt on starter mount for the LS4 that has been used a variety of transmissions. It likely would work for the 4T80 as well.[/smameless plug]
http://fieroguruperformance.com/?page_id=1558
cmechmann JAN 22, 07:53 PM
I recently replaced a 4T80 in a Deville. Slipping issues in 3rd after hot and no 4th from bad cooler issues. Not uncommon on a 19 year old radiator and cooler hoses. Heat will kill any transmission. Came in today for 1000 mile check. The Northstar had it's typical problems, but the trans was fine.
Another issue with swapping using a 4T80 is exhaust routing. Due to it's size, it makes for little room. The Northstar/4T80 routing is a nightmare, and I can't imagine an LT or LS being much better.
What I don't understand is what you have against a 4T65. If you what to use a LS4, that is what they are bolted to. GM beefed up the internals for a LS4. If you get a donor car with a LS4, everything else is already there. Trans, wiring, PCM, starter mounting. The people I here with LS4s that are going through transmissions abused them.
I have been running a 4T60e behind a Series 1 3800sc, then a Series II sc, then a 3800 n/a with the same transmission.
With the Series II sc and n/a you can save another 10lbs by using an N/W body 3.1/3.4 torque converter instead of using the large one that comes in the G/H bodies. Both the flywheels on the Series IIs I ran had bolt holes for either converter. The Series 1 I had holes drilled to use the smaller converter.
G-Man JAN 22, 08:46 PM
Thanks Guru. I had seen the track videos of that car. He was estimating 650+ horsepower and didn't do any kind of rebuild to either of the transaxles he used.

Good to know an SBC/80 combo has been used in the Fiero. Any idea how much cutting was done or whose adapter plate was used? I've tried searching for this but no luck. The only pics I can find of the Zumwalt showpiece are in my old FOCOA magazines and they aren't very good.

From what I've read, the control is similar between the 65 and 80 but there are enough differences where I'm wondering if it wouldn't be better to go with a trans and TCM from a 2006+ (trans controller is separate from the engine controller). It would depend on whether it would communicate with the ECM (E40/E67) for information sharing. Alternatively, maybe something from the aftermarket (PCS) could be used?

eta: cmechman, as the title says: I'm just kicking around ideas.
Gary

[This message has been edited by G-Man (edited 01-22-2018).]

fieroguru JAN 22, 11:27 PM
You might want to research the 2007+ Buick Lucerne.

It came with the N* and ran the E67 ecm (same as 2007+ LS4s), so either the N* E67 ecm is controlling the 4T80 or a compatible TCM is (T42 is used with the 4T65e-hd). Either way, it might be easier to get the LS4 (or other LS based engine) to run with the N* E67 ECM/TCM combo than trying to get something to control the 4T80. I would check the angles/placement of the crankshaft and cam sensors between the two engines. Most of the other items (injectors, tb size, timing, firing order, etc) can be changed in the tune.
Will JAN 23, 09:37 PM
58x Northstar has the crank sensor in the valley, but I don't know how the "skipped teeth" are indexed relative to TDC #1.
FieroWannaBe JAN 24, 10:33 AM

quote
Originally posted by cmechmann:
What I don't understand is what you have against a 4T65. If you what to use a LS4, that is what they are bolted to. GM beefed up the internals for a LS4. If you get a donor car with a LS4, everything else is already there. Trans, wiring, PCM, starter mounting. The people I here with LS4s that are going through transmissions abused them.


Transmission failures are very common for even stock LS4 owners. I can see why people are interested in something stronger.
I would look into the 6T75/6T70. GM never actually offered it with the metric bellhousing. So any V8 requires and adapter, but it has been validated in the heaviest of GM vehicles, and GM has versions living behind the turbo cadilllacs.
tampalinc JAN 24, 02:21 PM
I have been digging into putting a 6-sp auto and LS in my car for a while.
6T70 M7W was matted to the 2.0L I4 LTG Turbo in the Malibu and Regal.
2.0L I4 LTG Turbo also came matted to the F40 manual.
F40 mattes to the LS4, so would the 6T70 M7W mate to the LS4?
Gear Ratios
First: 4.484
Second 2.872
Third: 1.842
Fourth: 1.414
Fifth: 1.000
Sixth: 0.742
Effective Final Drive Ratio: 2.77